SS4DarthPayne said:
where and how did these images come about? Shot on set with an actual camera, and then edited later? And would I be correct in assuming they have essentially been promo images for the last forty years?
That's exactly what they are. Tons of these (for all kinds of movies) can be found here: http://www.moviestillsdb.com/search?query=star+wars
But you need to buy download credits to actually download the full size versions.